A distinguishing feature of humans as a species is our ability to communicate with each other. Our methods of communication have become ever more sophisticated and have led to the development of wireless communications. Generally, wireless communications are communications that are transmitted through the use of radio frequency (RF) technology. Wireless communications include communications that are transmitted through the use of wireless units such as cellular telephones, mobile telephones, car phones, personal communication service (PCS) units, pagers, and the like, and also may include appropriately equipped computers, computer peripherals, and the like.
A wireless unit is particularly useful to a person on the move. For example, a person may use his or her wireless unit while driving a car. The wireless communications service to the person's wireless unit is provided typically by a service provider that may also he referred to herein as a carrier. Typically, a person who obtains wireless communications service from a service provider is generally referred to herein as a subscriber or a user. A subscriber may make or receive communications with his or her wireless unit. The term “communication” is used herein to refer to any call, message, announcement, or other exchange of data or information, whether analog or digital, that may be received on a wireless unit or transmitted from a wireless unit, and/or may be received or transmitted from a wireless unit that is operating as part of any other device such as a computer.
When a user initiates a communication on his or her wireless unit, a base station in or serving a predetermined geographic area wherein the subscriber is located receives the communication. The geographic area that is served with wireless communications service by the carrier is referred to herein as the service area of the service provider. The service provider typically operates a wireless communications network or system to provide wireless communications service to the geographic area. The wireless communications network or system includes the referenced base station, and other elements such as mobile switching centers (MSCs). The wireless communications network also includes elements that interface with the public switched telephone network (PSTN), and other networks and systems so as to provide for communications between and among parties using wireless units or using wireline units.
Upon receipt of a communication from a wireless unit of a user, the base station transmits the communication to a mobile switching center (MSC) (sometimes referred to as a mobile-service switching center or mobile telecommunications switching office (MTSO), or switch). In response to the receipt of the communication, the MSC further routes the communication as appropriate. This routing may take the communication to and through the PSTN, to and through the same wireless communications system, to and through another wireless communications system, or combinations thereof.
In addition to making a call, a subscriber may receive a communication on his or her wireless unit from a caller. The caller directs his or her communication to the number associated with the subscriber's wireless unit, which is referred to herein as the mobile number of the wireless unit. The mobile number may be the mobile identification number (MIN) of the wireless unit. The communication is routed through the PSTN, through other networks, and/or wireless communications systems until the communication reaches the MSC serving the subscriber's wireless unit. This MSC may be referred to as the serving MSC or the serving switch. The serving MSC then further routes the communication to the wireless unit.
As noted, a wireless unit is particularly useful when a subscriber is on the move such as when the subscriber is driving a car. The subscriber's mobility may take the subscriber out of the service area served by the service provider from whom the subscriber subscribes. In other words, the subscriber's mobility may take the subscriber out of his or her home service area served by his or her home service provider or home carrier. The subscriber may move so as to be located in another service area that is served by a different service provider with whom the subscriber has no direct business relationship. The subscriber is said to be “roaming” out of his or her home service area and may be referred to as a “roamer”, or “roaming subscriber” in a visited service area that is served by a visited system. To provide a roaming subscriber with communications service, service providers have agreed to follow certain procedures in the processing of communications with respect to each other's subscribers. Generally, a roaming subscriber is validated and may be authenticated by the visited system, which also may be referred to as the visited service provider. Both of these processes (validation and authentication) are used to prevent fraudulent use of wireless units and for other reasons. General descriptions of these processes and other information about wireless communications systems may be found in the book entitled Cellular and PCS—The Big Picture by Lawrence Harte, Steve Prokup and Richard Levine (McGraw-Hill 1997).
Generally, in validation, when a wireless unit initiates a communication in a service area other than its home service area, the visited system serving that visited service area attempts to find the wireless unit's identification (also referred to as registration information) in the visitor location register (VLR) of an appropriate MSC in the visited system (MSC-V). If the visited system does not find the identification, then the wireless unit is determined to be not registered with the visited system. Prior to being provided with communications service in the visited system, a wireless unit typically needs to be registered in the visited system.
To register the wireless unit in the visited system, the MSC-V takes certain steps. Using the wireless unit's identification (which generally may include its mobile number, and electronic serial number (ESN), and/or mobile identification number (MIN), if different from the mobile number), the visited system sends a message to the wireless communications system (“home system”) which generally provides wireless communications service to the subscriber. Alternatively, or in addition, the visited system may send a message to a clearing house or other entity other than the home system. The message from the visited system requests validation of the visiting wireless unit. The home system checks a home location register (HLR) in an appropriate MSC (MSC-H) of its system. The clearing house or other entity may check a database, table, or other storage medium of its system. A comparison is made with respect to the identification regarding the wireless unit to determine if the wireless unit is valid. If the wireless unit is valid, then the HLR of the MSC-H and/or the clearing house or other entity responds to the serving MSC in the visited system that the validation was successful. The HLR in the home system and/or clearing house or other entity generally keeps track of the information about the location of the subscriber in a visited system for use in the future routing of calls, etc.
After the serving MSC in the visited system receives confirmation that the visiting wireless unit is valid, the communication initiated by the visiting wireless unit is processed. The VLR of the serving MSC may then temporarily store the visiting wireless unit's information to validate the identity of the wireless unit itself rather than requesting validation again for the next call.
Validation generally is the mechanism for providing information to the subscriber's home system with respect to the subscriber's location in a visited system. With this location information, the home system then may process calls that are received for the roaming subscriber. In particular, when a home system receives a call for its subscriber, the MSC in that home system (MSC-H) checks its HLR to determine if the wireless unit is operating in the geographic area of the home system. The MSC-H may find that the wireless unit is not located in the geographic area of the home system, but rather, is roaming in a visited system. The MSC-H may have location information with respect to the wireless unit. If so, the MSC-H sends a request to the visited MSC (MSC-V) for information that will help the MSC-H in routing the call to the subscriber.
The above processes of validation and call processing are carried out generally with respect to communications that occur within the United States. However, wireless communications between the United States and foreign countries or wireless communications between foreign countries have been problematic. Problems arise because the processes described above may not be carried out with respect to communications between the United States and a foreign country or between foreign countries because of the differences in the wireless systems in the respective countries. A wireless system and its related wireline system in a particular country may not be networked with the wireless system and its related wireline system in a foreign country. Thus, in some cases, information regarding a wireless unit's roaming location in a visited system is not reported properly to the home system. The lack of reporting is especially problematic between countries having differences between their respective wireless systems. Without location information regarding a wireless unit, the home system is unable to route calls to the wireless unit.
In addition, the problems associated with the fraudulent use of wireless units are prevalent in the United States and abroad. Once a wireless unit is registered in a visited system, the wireless unit may be especially vulnerable to being cloned or otherwise fraudulently used.
Accordingly, there is a need for methods and systems that provide location information regarding a wireless unit that is roaming in a visited system to a home system of the wireless unit. Further, there is a need for methods and systems that provides safeguards so as to prevent fraudulent use of wireless units as they roam between and among countries or systems.